The X32 scn files can't be loaded directly with the app. But you can save offline scenes from within the app itself - note that the file format is not compatible with the mixer.
Otherwise you would have to import the scn file directly via a USB stick to the mixer

The "hold" detection for opening the horizontal popup can't be applied to the regular channel faders as they are much more sensitive to motion.
Therefore the "hold" detection would either interrupt a very slow fader movement by opening the popup, or be way to hard to open as you have to keep the finger precisely on the same location.